ASRA Pain Medicine consensus practice infection control guidelines for regional anesthesia and pain medicine: Ultrasound probes as a source of surgical site infection
Myron Yaster MD, Lynn Martin MD MBA, and Kim Strupp MD
Today’s PAAD by Provenzano et al.1 is a must read for EVERY practicing anesthesiologist and pain management specialist. This encyclopedic review by the American Society of Regional Anesthesia and Pain Medicine (ASRA) provides evidence-based recommendations on risk mitigation of infectious complications associated with the practice of regional anesthesia and pain management. “The scope of these current recommendations extends beyond neuraxial blocks and includes various nerve blocks (peripheral and spinal), chronic pain procedures, and minimally invasive surgical techniques used in acute and chronic pain management.”1 Over the next 2 weeks we will review several of the recommendations for procedures that are most appropriate for pediatric anesthesiologists. Today’s PAAD discusses an issue that has long troubled me, namely, how to safely handle ultrasound equipment and prevent nosocomial infections (bacterial and viral) in patients undergoing interventional and diagnostic procedures in our daily practice. Myron Yaster MD
Original article
Provenzano DA, Hanes M, Hunt C, Benzon HT, Grider JS, Cawcutt K, Doshi TL, Hayek S, Hoeltzer B, Johnson RL, Kalagara H, Kopp S, Loftus RW, Macfarlane AJR, Nagpal AS, Neuman SA, Pawa A, Pearson ACS, Pilitsis J, Sivanesan E, Sondekoppam RV, Van Zundert J, Narouze S. ASRA Pain Medicine consensus practice infection control guidelines for regional anesthesia and pain medicine. Reg Anesth Pain Med. 2025 Jan 20:rapm-2024-105651. doi: 10.1136/rapm-2024-105651. Epub ahead of print. PMID: 39837579
We’ve previously discussed the role of anesthesia providers in infection control in several PAADs, most recently on March 12, 2024 (https://ronlitman.substack.com/p/role-of-anesthesia-providers-in-infection ). In that PAAD, I (LM) shared an experience from my time as the chief of at Seattle Children’s Hospital, where the hospital’s Chief Medical Officer presented evidence that anesthesia care in the ORs, cardiac cath labs, and interventional radiology suites was linked to higher rates of catheter-associated blood stream infections (CABSI) rates. To address this issue, we realized that the non-sterile gloves were the vector for contamination and established clean (anesthesia cart and medication administration without gloves) and dirty (anesthesia machine, computer, and patient with glove) zones and hand hygiene whenever going between zones, leading to a 35% reduction in the hospital CABSI rate.2 In today’s PAAD we will review ASRA’s recommendations for ultrasound-guided regional anesthesia and pain procedures. Ultrasound-guided procedures provide multiple opportunities for cross-infection of patients, including: 3,4
· Poor hand hygiene
· Contamination of the probe, cord, and keyboard (despite low-level disinfection (LLD))
· Use of contaminated coupling gel.
Globally, these infection concerns have resulted in the development of ultrasound-specific infection control recommendations, yet guidelines from multiple agencies and societies are mostly ignored. How to get practitioners to implement guidelines is a recurrent theme we’ve discussed in many previous PAADs and will continue to focus on in the future.
“Ultrasound equipment, and in particular ultrasound transducers (probes) can be a source of nosocomial infections (bacterial and viral) in patients undergoing interventional and diagnostic procedures. When not covered with a transducer cover, the transducer can come into direct contact with the patient. Coupling agent or gel can also be a vector for infection transmission, and redundant gel on these transducers can allow bacteria and viruses to survive for hours to months on surfaces, depending on the pathogen. Multiple studies have demonstrated the risk of contamination and the risk of cross-infection through ultrasound equipment.”1 Even visibly clean ultrasound probes can still harbor clinically significant bacterial burden that can survive on the ultrasound transducers for up to several months.
From our perspective perhaps the most critical recommendation is that “Single-use sterile ultrasound cover and sterile ultrasound gel are recommended for every procedure.” Further, some transducer covers may contain microperforations and can tear, so the use of a transducer cover is not a substitute for following a standardized disinfection process. Tegaderm covering of the probe is NOT suitable and using ultrasound devices without any cover can significantly increase the risk of nosocomial infection.
Specifically:
· Ultrasound probes, even when clean, can act as vectors for transmission of infectious material between individuals. Level of certainty: high.
· The use of sterile probe covers is likely beneficial when performing ultrasound-guided regional anesthesia and pain interventions. Level of certainty: moderate.
· Transparent adhesive film dressings are not endorsed by US manufacturers or approved by the FDA for use as ultrasound probe covers. Level of certainty: high.
Between cases, the ultrasound transducer and cable require a systematic process for cleaning, disinfection, and storing. Low level disinfection and cleaning with soapy water, sterile paper towels, and ethanol-soaked wipes will help remove all the visible gel, bioburden, and soil on the transducers. “High-level disinfection (HLD) with substances like glutaraldehyde, hydrogen peroxide, peracetic acid, hypochlorite, phenol, and chlorhexidine can remove all microorganisms except bacterial spores, and is effective against high-risk pathogens.5 In summary:
· The ultrasound transducer can be a vector for infection. Level of certainty: high.
· LLD is effective for disinfection of a transducer used for non-critical procedures with intact skin (eg, diagnostic ultrasound over intact skin areas). Level of certainty: high.
· HLD is effective for disinfection of the transducer used for semicritical (ie, mucous membranes and non-intact skin) procedures. Level of certainty: high.
Finally, ultrasound gel is another infection vector. The simplest remedy is only use single use sterile gel.
Again as we’ve discussed in many previous PAADS guidelines are great, but implementation is the key. Your infection control protocols must evolve to align with the latest guidelines. Build system process to facilitate compliance. For example, in Seattle the LLD is completed after ever procedure by our anesthesia techs. The techs also facilitate reliable use of probe covers and sterile gel in their set-up immediately prior to the block time out! Aside from educating the team and advocating for change, regular AUDITING of clinical practice is paramount to ensuring compliance with these guidelines.
What do you think? Are you ready to abandon naked ultrasound probes and/or Tegaderm? Multi use ultrasound gel single use tubes? Send your thoughts and comments to Myron who will post in a Friday reader response.
References
1. Provenzano DA, Hanes M, Hunt C, et al. ASRA Pain Medicine consensus practice infection control guidelines for regional anesthesia and pain medicine. Regional anesthesia and pain medicine 2025 (In eng). DOI: 10.1136/rapm-2024-105651.
2. Martin LD, Rampersad SE, Geiduschek JM, Zerr DM, Weiss GK, Martin LD. Modification of anesthesia practice reduces catheter-associated bloodstream infections: a quality improvement initiative. Paediatric anaesthesia 2013;23(7):588-96. (In eng). DOI: 10.1111/pan.12165.
3. Westerway SC, Basseal JM, Brockway A, Hyett JA, Carter DA. Potential Infection Control Risks Associated with Ultrasound Equipment - A Bacterial Perspective. Ultrasound Med Biol 2017;43(2):421-426. (In eng). DOI: 10.1016/j.ultrasmedbio.2016.09.004.
4. Skowronek P, Wojciechowski A, Leszczyński P, et al. Can diagnostic ultrasound scanners be a potential vector of opportunistic bacterial infection? Med Ultrason 2016;18(3):326-31. (In eng). DOI: 10.11152/mu.2013.2066.183.sko.
5. Link T. Guideline Implementation: Manual Chemical High-Level Disinfection: 1.5 www.aornjournal.org/content/cme. AORN journal 2018;108(4):399-410. (In eng). DOI: 10.1002/aorn.12373.